Lecture 25: Clinical Cases - ECG

Question 1

Sinus tachycardia on ECG refers to?

Sinus bradycardia on ECG refers to?

Answer 1

HR > 100

HR <60

Question 2

What are premature beats?

Answer 2

Out of sync beats that can appear in p (atrial), ST (junctional) and QRS (ventricular) waves

Question 3

How does premature atrial contraction present on ECG?

Answer 3

Extra p wave is present

Question 4

What can cause a premature ventricular contraction (PVC)?

How can this present on an ECG?

Answer 4

• AP coming from the ventricle not the SA node, causing premature ventricular beats
• Wide QRS, extra prominent QRS.

Question 5

What is the difference between unifocal and multifocal PVCs?

Answer 5

Unifocal PVCs appear in the same leads = same part of ventricle is affected
Multifocal PVCs appear in different leads = various parts of ventricle is affected, more concerning

Question 6

What is physiologically happening in Vtach?

Answer 6

Ventricular myocytes are very irritable and keep depolarizing

Question 7

What characterizes V Tach in an ECG?

Answer 7

6 straight PVCs (look like wide QRS). If patient is exhibiting 3-4 PVCs, medicate to prevent VTach

Question 8

How does SVT present on an ECG?

Answer 8

Usually tachy (150-180 BPM), very narrow QRS, so fast p waves are hidden/merged

Question 9

How does A-Fib present on an ECG?

Answer 9

No discernable p wave (just quivers), irregular QRS rhythm (cannot count the QRS rate properly)

Question 10

How does 1st degree AV Block present on an ECG?

Answer 10

Prolonged PR intervals (> 1 large box)